jarek/6529: fix flaky test (#6536)

* #6529: add volatile * #6529: add synchronizedList * #6529: add unmodifiableList * #6529: add synchronizedList * #6529: create copy of list * #6529: clean * #6529: make a copy in getters * #6529: make clear method as synchronized
twosigma · Dec 19, 2017 · fa7eb07 · fa7eb07
1 parent 7144103
commit fa7eb07
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Showing 2 changed files with 26 additions and 16 deletions.
diff --git a/kernel/base/src/test/java/com/twosigma/beakerx/KernelSocketsTest.java b/kernel/base/src/test/java/com/twosigma/beakerx/KernelSocketsTest.java
@@ -21,10 +21,13 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.synchronizedList;
+
 public class KernelSocketsTest extends KernelSockets {
 
-  private List<Message> publishedMessages = new ArrayList<>();
-  private List<Message> sentMessages = new ArrayList<>();
+  private volatile List<Message> publishedMessages = synchronizedList(new ArrayList<>());
+  private volatile List<Message> sentMessages = synchronizedList(new ArrayList<>());
 
   @Override
   public void publish(Message message) {
@@ -37,15 +40,19 @@ public void send(Message message) {
   }
 
   public List<Message> getPublishedMessages() {
-    return new ArrayList<>(publishedMessages);
+    return copy(this.publishedMessages);
   }
 
   public List<Message> getSentMessages() {
-    return new ArrayList<>(sentMessages);
+    return copy(this.sentMessages);
+  }
+
+  private List<Message> copy(List<Message> list) {
+    return asList(list.toArray(new Message[0]));
   }
 
-  public void clear() {
-    publishedMessages = new ArrayList<>();
-    sentMessages = new ArrayList<>();
+  public synchronized void clear() {
+    publishedMessages = synchronizedList(new ArrayList<>());
+    sentMessages = synchronizedList(new ArrayList<>());
   }
 }
diff --git a/kernel/base/src/test/java/com/twosigma/beakerx/KernelTest.java b/kernel/base/src/test/java/com/twosigma/beakerx/KernelTest.java
@@ -16,6 +16,7 @@
 package com.twosigma.beakerx;
 
 import static com.twosigma.beakerx.kernel.magic.command.ClasspathAddMvnDepsMagicCommandTest.TEST_MVN_CACHE;
+import static java.util.Collections.unmodifiableList;
 
 import com.twosigma.beakerx.autocomplete.AutocompleteResult;
 import com.twosigma.beakerx.evaluator.Evaluator;
@@ -59,6 +60,7 @@
 import com.twosigma.beakerx.kernel.msg.MessageCreator;
 import com.twosigma.beakerx.kernel.threads.ExecutionResultSender;
 import com.twosigma.beakerx.message.Message;
+
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Path;
@@ -68,6 +70,7 @@
 import java.util.Map;
 import java.util.Observer;
 import java.util.Set;
+
 import org.apache.commons.io.FileUtils;
 import org.assertj.core.util.Lists;
 
@@ -107,18 +110,18 @@ public KernelTest(String id, Evaluator evaluator) {
     KernelManager.register(this);
   }
 
-  private void initMavenResolverParam(){
+  private void initMavenResolverParam() {
     this.mavenResolverParam = new MavenJarResolver.ResolverParams(
-        new File(TEST_MVN_CACHE).getAbsolutePath(),
-        getTempFolder().toString() + MavenJarResolver.MVN_DIR,
-        true);
+            new File(TEST_MVN_CACHE).getAbsolutePath(),
+            getTempFolder().toString() + MavenJarResolver.MVN_DIR,
+            true);
   }
 
   private void initMagicCommands() {
     this.magicCommandTypes = new ArrayList<>();
     this.magicCommandTypes.addAll(Lists.newArrayList(
             new MagicCommandType(JavaScriptMagicCommand.JAVASCRIPT, "", new JavaScriptMagicCommand()),
-            new MagicCommandType(JSMagicCommand.JAVASCRIPT,"", new JSMagicCommand()),
+            new MagicCommandType(JSMagicCommand.JAVASCRIPT, "", new JSMagicCommand()),
             new MagicCommandType(HtmlMagicCommand.HTML, "", new HtmlMagicCommand()),
             new MagicCommandType(HtmlAliasMagicCommand.HTML, "", new HtmlAliasMagicCommand()),
             new MagicCommandType(BashMagicCommand.BASH, "", new BashMagicCommand()),
@@ -268,19 +271,19 @@ public EvaluatorParameters getSetShellOptions() {
   }
 
   public List<Message> getPublishedMessages() {
-    return publishedMessages;
+    return unmodifiableList(publishedMessages);
   }
 
   public List<Message> getSentMessages() {
-    return sentMessages;
+    return unmodifiableList(sentMessages);
   }
 
   public void clearPublishedMessages() {
-    this.publishedMessages = new ArrayList<>();
+    this.publishedMessages = new ArrayList<>(new ArrayList<>());
   }
 
   public void clearSentMessages() {
-    this.sentMessages = new ArrayList<>();
+    this.sentMessages = new ArrayList<>(new ArrayList<>());
   }
 
   public void clearMessages() {